Evinrude D.I. 2002 Vapor Separator

[hmattos]

We have been struggling with the vapor separator valve on a 2002 Evinrude 225 hp V6 Direct Injection engine.
The problem is the valve sticks when it is parked for more than a few days and when you restart the engine it will misfire badly at high revs - usually shows up the first time you get to 4500 revs under load. If you leave the throttle open it will often slow right back to 1000 revs. Leave it running in neutral for 30 secs and then accelerate and it will go right back to 4500 revs for a short while - less than one minute.

We can fix it by stripping the vapor separator - a very easy job on the trailer but a dog of a job on the water - and cleaning and setting the vapor separator float valve.
I can only guess that the valve sticks open and allows air in when the fuel flow rate is very high...

Has anybody come across this one?

Regards

Hugh Mattos
www.explorermarine.co.uk

[redtech]

check fuel pressure between lift pump and vapor separator (3-4psi)
vacuum before lift pump is no more than 3"hg
if there is a problem before the seperator your high pressure pump can try to pull fuel from the tank to make up for it (down side the high pressure pump soon dies)

[hmattos]

We have tested these at idle and slow revs, at no load, on the trailer, and all seems ok. However, I have not dared to try it at full revs under load on the water. Any other ideas?

Regards
Hugh Mattos

[redtech]

i'm sorry to say this but if the problem is at wide open throttle you have to test at w.o.t
if testing on the water is not possible going to a shop with a dyno is the only opption
i've been there and testing things like this in water is not fun less fun if it's rainning, foggy, or snowing
to pull yourself away from the motor it is ok to use long pieces of fuel line
also you can back the trailer in and see if the problem happens at w.o.t. on the trialer (noisey and you will not get high rpms but it does load the engine)